C-10, C-12 and C-15 On-highway Engines Caterpillar

Probable Causes

The probable root causes are listed in order below:

• Diagnostic codes

• Engine rating

• Customer specified parameters (normal operation)

• Cold mode operation

• Individual malfunctioning cylinder

• "Power train data link"

• Personality module

• Torque limit switch

Recommended Actions

Perform the following diagnostic procedures in order:

1. Certain diagnostic codes may cause poor performance. These diagnostic codes are intended to protect the engine.

   1. Connect the Caterpillar Electronic Technician (ET) to the data link connector.

   2. Check for active codes and/or for logged codes. Troubleshoot any codes that are present before continuing with this procedure.

2. Check the "Advertised Power" for the engine.

   Note: This step is only applicable to C-12 engines.

   1. Access the "Configuration" screen on Cat ET.

   2. Check the "Advertised Power" for the engine.

      If the engine is a C-12 and the engine is rated at 505 HP, then the loss of power may be due to normal operation.

   3. Check for diagnostic codes. If the 166-11 diagnostic code is active and/or logged, then the engine has been derated due to normal operation.

3. Check customer specified parameters.

   1. Verify that the complaint is not normal operation (programmed parameter).

   2. Check the following parameters:
      • "Lower Gears Engine RPM Limit"

      • "Intermediate Gears Engine RPM Limit"

      • "Gear Down Protection Engine RPM Limit"

   3. Set each parameter to the parameter's maximum value one at a time and determine whether the problem is corrected.

4. Check cold mode operation.

   Note: This is normal operation if the problem occurs only after start-up in cold weather.

   1. Monitor Cat ET in order to verify that the engine has progressed from cold mode.

      An active cold mode is indicated in the upper corner of any status screen.

5. Check for an individual malfunctioning cylinder.

   1. Ensure that the electronic unit injector connector (J300/P300) is fully connected and ensure that the electronic unit injector connector (J300/P300) is free of corrosion.

   2. Ensure that the engine harness connector for the Engine Control Module (ECM) (J2/P2) is fully connected and ensure that the engine harness connector (J2/P2) is free of corrosion.

   3. Use the cylinder cutout test. Access the cylinder cutout test by selecting the "Diagnostic Menu" and the "Diagnostics Test Menu". Run the cylinder cutout test in order to disable each cylinder. Disabling each cylinder allows the technician to isolate the misfiring cylinders.

      If the misfiring cylinder can be isolated to a specific cylinder, refer to Troubleshooting, "Injector Solenoid Circuit - Test".

6. Check the "Power train Data Link". Ensure that the SAE J1922 or the SAE J1939 Power train Data Link is not limiting the power.

   1. Monitor the "Power train Data Link" Status screen while the vehicle is experiencing problems.

      If the "Power train Data Link" Status screen indicates that the "Power train Data Link" is limiting the power or the rpm, verify that this is not normal operation. If this is not normal operation, refer to the vehicle OEM for repairs.

7. Check the ECM or the personality module.

   1. Verify that the correct personality module has been installed.

      Refer to Troubleshooting, "ECM Memory - Test".

8. Check the torque limit switch.

   1. Check the setting for the customer parameter for the "Torque Limit".

      If the "Torque Limit" is programmed below 3400 N·m (2500 lb ft), check the status screen for the torque limit switch. Ensure that the status screen indicates that the torque limit switch is OFF. If the status of the torque limit switch is ON and a "Torque Limit" is programmed, the system is operating correctly. If the switch that is connected to this signal input is not switching ON and switching OFF, refer to Troubleshooting, "PTO Switch Circuit - Test".